You can try to get an instruction sheet for the sander by calling 1-800-803-6775. I am not sure if this is still available but we will try to get one for you. Always unplug the sander before doing any adjusting or replacing sanding belts. To change the sanding belt you should loosen the tension adjusting knob until the belt is loose on the rollers. The belt will slide off the rollers and a new belt slides over the rollers. Tighten the tension until the belt stays on the rollers with the sander running. It should be as loose as you can run it without it walking on the rollers.
how to change sandpaper on belt sander craftsman Related Question:
How do you release a Craftsman belt sander?
Locate the tension release lever mounted on the idler pulley support, which is located between the two belt pulleys. Slide the lever up and toward the front of the sander, releasing tension on the belt.
What size belt does a Craftsman belt sander use?
Attach Craftsman’s 4 x 36-in. Sanding Belt, 50-Grit to your belt sander to produce a smooth and professional-looking surface on wood, metal, plastic, fiberglass and more.